1. Field of the Invention
This invention relates to earth working apparatus and in particular to means for transferring an impact force from a force means to a ripper for loosening earth and the like.
2. Description of the Prior Art
In U.S. Pat. No. 3,770,322 of Delwin E. Cobb et al., owned by the assignee hereof, an improved apparatus for fracture of material in situ with stored inertial energy is disclosed. In one embodiment of the apparatus therein, a hammer is impacted against a ripper shank which is pivotally supported on a frame. The hammer is pivotally supported on the ripper shank. The impact surface of the hammer is shaped arcuately and engages the ripper shank in a groove thereof for reducing the possibility of rock and other material from coming between the impact surfaces.
The impact surfaces are shaped so that initial contact occurs near the center of rotation and then, as the shank and hammer deform the contact surface, expands toward the lower edge. The disclosed construction is provided to reduce the impact stress in effecting a cushioned impact wherein the initial impact velocity is reduced.
In the illustrated embodiment, the surface of the ripper shank engaged by the impact hammer is substantially straight and the impact force is delivered through a hammer toward the initial point of contact of the hammer surface with the ripper shank surface.